I didn't much care for Tales of Vesperia either. It's not that it was a bad game really, I just didn't really like the battle system all that much, and I encountered a very tough boss early in the game that I couldn't kill, so that was the end of that game for me. It seemed okay, and had I not encountered that boss I probably would have continued playing, but it wasn't as good as Lost Odyssey or Blue Dragon for me.
I agree that Blue Dragon is a bit too easy, but there is a downloadable DLC patch that introduces higher difficulty modes.
"Dubbed the Ultra Hard Mod, the new content has three aspects. The first is Game Plus, which allows you to start a new game using a saved file from near the end. The other two are specifically for the masochistic: Hard Mode, reportedly twice as challenging as normal, and Impossible, which is meant to play with characters starting at level 50 or higher. (If you want to do the Impossible at level 10, however, by all means go for it. Let us know how that works out.)"
I don't think Blue Dragon should be dismissed as "just a kid's game" though. Yes, the main characters in the game are kids, and the world is bright, colorful and, I guess you could say, "cartoon-ish", but I still feel the main game has a lot of depth that adults can enjoy. There's optional content in the way of very hidden items and optional bosses at the end of the game that you have to grind for many hours in order to defeat. I can't imagine that type of content was made with kids in mind. Maybe it's me though. I definitely had a blast with Blue Dragon and would recommend it to those who thought Lost Odyssey was great as well.
I don't agree that Blue Dragon didn't have a soul either. I'm not sure exactly what having a soul entails, but Blue Dragon has plenty of charm, character, humor, etc. The story is great with a very memorable villain and some great cutscenes. The gameplay is very addictive, and in order to master it and reach level 99 it takes a very "hardcore" mindset. Building a character with the job system is a blast, as you can mix and match skills from different jobs to your heart's content. The main quest takes you to some fantastic locations, like a place where the inhabitants are living murals painted on the walls. And finally, the music is excellent and very memorable.
If you want to really enjoy Blue Dragon, approach it with an open mind and don't listen to reviews. You'll find a game that is completely charming and beautiful that will grow on you, and in time you'll be wanting to complete it because you find yourself loving it. At least, that's how it happened for me…
Anyway, back to Xenoblade!